<!DOCTYPE html>
<html>
	<head>
		<meta charset="UTF-8">
		<title></title>
		<script type="text/javascript">
			/**var width;
			alert(width);
			var h=null;
			alert(h);
			alert(width==h);**///true?
			var w=15.6;
			alert(w+":"+typeof(w));
			w=false;
			alert(w+":"+typeof(w));
			w="泰豪";
			alert(w+":"+typeof(w));
			w=document.getElementById("xxx");
			alert(w+":"+typeof(w));
			w=null;
			alert(w+":"+typeof(w));
			
		</script>
	</head>
	<body>
	</body>
</html>

